Improvement in springs for beds, sofas



.IQHN s'EARsgor CORTLAND, .NEW YORK.

Letters Patent No. 110,293, datedDecemberg, 1870.

IMPROVEMENT lN ASPRINGS FOR BEDS, SQFS, &c'.

The Schedule reifen-edito in these Letters Patent and making part oi' the same.

To all fwhom it muy concern;

Be it known that I, JOHN SEARS, of Cortland, in the county of Cortland and State of New York, have invented a new andimproved Spiral Spring i'or Beds, Sofas, Chairs, &c.; and I do hereby declare that the following is a full and exact description thereof, reference being had to the accompanying drawings and to the letters of reference marked thereon.

To enable others sliiiled in the arts to make-and us my invention, I will proceed to Adescr ibe its construction and operation.

A A is the Support;- or slut into which the springcoil is secured, and upon which it rests. K The size of the coil is to be adapted to the use intended. I take any suitable-sized wire and form my coil in conical form, with uniform or nearly uniibrm contraction from base to top. 'lhe top terminates in a stem, cut with a screw-thread, and sutiicient in length to secure and hohl a cap, as shown in Figure 1. Thecoii is secured to the base or slat in anyconveuient or suitable manner. The. spring shonldbc so wrought in thecoil as to diminish the altitudinalspaces in the c oil'in ratio with the decrease in the diminishing diameter of the coil.

In the slat or rest, at \V, I cut ont a concave corering the space embraced within the wire, leaving in the center a cone, It.

The cap H is ot. anyf4- convenient size, and is screwed onto the thread D. lo this cap may be 4securedtbe upper cross-Slat in any vsuitable, manner.

The advantages of my spring consist in its dura.- bility and operation.

Thoseheretofore used are tbe double'spiral, having broad bases at top and bottom, and theirtapering points meeting in the center. These are expensive in construction, liable to get out of order, and are very unsatisfactory in operation.

'lhe single spiral hitherto used is made with an uncertain coil, and tern'linating the. decreasing of the coil at about midway, and from thence running up in form of a stem.

\Vhen pressure is brought to bear on the spiral the =stem is pressed down, being; weaker than the expanding coil below, and doubles in at -t-he point where the used, whether beds, chairs, or in other articles, they work with perfect uniformity and prove equally durable.

Vhat I claim as my invention, and desire to secure by Letters llatent, is-l 'lhe spring (l, with screw-point D and cap H, inv combination with the base A, with concave YV and cone R, as ,shown and described. l

. JOHN SEARS. Vituesses:

f ARTHUR' HOLMES,

J. H. 'IALMEm rfid, 

